A centralized exhaust pneumatic amplifier

Abstract

The application discloses a centralized exhaust type pneumatic amplifier and belongs to the technical field of pneumatic control equipment. The amplifier comprises an upper cover, a middle plate and a lower body which are sequentially stacked and fixed from top to bottom. A first diaphragm is press-fitted between the upper cover and the middle plate, and a second diaphragm is press-fitted between the middle plate and the lower body, thereby forming A cavity, B cavity and C cavity. A gas collecting chamber is arranged in the lower body, an exhaust passage is arranged in the middle plate and communicates with the B cavity, an exhaust collecting passage is arranged in the lower body and communicates with the exhaust passage, the bottom of the exhaust collecting passage communicates with the gas collecting chamber, and the bottom of the gas collecting chamber is provided with a centralized exhaust port. The gas in the B cavity is sequentially collected to the gas collecting chamber through the exhaust passage and the exhaust collecting passage and then discharged, the exhaust path is reconstructed, the pressure of the collected gas is uniform, the exhaust is smooth, a filter element, an exhaust plate and other protective devices can be conveniently installed at the centralized exhaust port, and the entry of external dust and rainwater into the amplifier is effectively prevented.

Description

Technical Field

[0001] This invention relates to the technical field of pneumatic control equipment, specifically a centralized exhaust pneumatic amplifier. Background Technology

[0002] As the core component of valve positioners, pneumatic amplifiers are widely used in process control systems in industries such as petroleum, chemical, and power. Their function is to amplify the control signal output by the positioner, drive the actuator to move, and achieve precise adjustment of the valve opening. Traditional pneumatic amplifiers usually adopt a diaphragm structure, which includes three main bodies: an upper cover, a middle plate, and a lower body. Multiple chambers are formed by the diaphragm, and the valve core is driven by the air pressure difference to achieve air path switching and control.

[0003] However, existing pneumatic amplifiers have significant drawbacks in harsh outdoor environments: First, the exhaust port is usually directly exposed to the outside of the housing, allowing rainwater and dust to easily enter the amplifier and damage precision components such as diaphragms and valve cores. Second, in the low temperatures of northern winters, the exhaust port is prone to icing and blockage, causing amplifier failure. Third, direct exhaust generates considerable noise, affecting the operating environment. To address these issues, existing technologies include improvements such as adding dust covers or silencers to the outside of the exhaust port. However, most of these solutions only add external protective devices, which are passive protections and fail to fundamentally solve the problems of low protection effectiveness and poor exhaust flow caused by an unreasonable exhaust path design.

[0004] Therefore, there is an urgent need for a pneumatic amplifier that can reconstruct the exhaust path from the inside, achieve active protection, and improve adjustment accuracy and stability. Summary of the Invention

[0005] The purpose of this invention is to provide a centralized exhaust pneumatic amplifier to solve the problems of existing pneumatic amplifiers where the exhaust port is directly exposed to the external environment, causing rainwater and dust to easily enter and damage the components, and the exhaust port is prone to freezing and clogging in low-temperature environments, affecting the normal operation of the product.

[0006] A centralized exhaust pneumatic amplifier includes an upper cover, a middle plate, and a lower body, which are stacked and fixedly connected from top to bottom. A first diaphragm is press-fitted between the upper cover and the middle plate, and a second diaphragm is press-fitted between the middle plate and the lower body. A cavity A is formed between the first diaphragm and the upper cover, a cavity B is formed between the first diaphragm and the second diaphragm, and a cavity C is formed between the second diaphragm and the lower body. The amplifier is characterized by: The lower body is provided with an air collection chamber; The middle plate is provided with at least one exhaust channel communicating with the B cavity; The lower body is provided with at least one exhaust collection channel that corresponds to and communicates with the exhaust channel one by one, and the bottom of each exhaust collection channel is connected to the gas collection chamber. The bottom of the gas collection chamber is provided with a centralized exhaust port. The gas in the B chamber is collected in the gas collection chamber through the exhaust channel and the exhaust collection channel in sequence, and then discharged through the centralized exhaust port.

[0007] By setting up a gas collection chamber inside the lower body, and setting up an exhaust channel and an exhaust collection channel inside the middle plate and the lower body respectively, the gas in cavity B is first collected into the gas collection chamber and then discharged through the centralized exhaust port, thus reconstructing the exhaust path. Compared with the prior art that directly exposes the exhaust port to the outside of the shell or only adds a protective cover to the outer part, this technical solution has the following advantages: Active guidance and collection: The originally dispersed exhaust gas is actively guided to the gas collection chamber through the internal process holes, avoiding disorderly gas emission; Centralized protection: After the gas is collected, it is discharged through a centralized exhaust port, which makes it easy to install protective devices in a single location, reducing protection costs and improving protection efficiency; Pressure equalization: The gas gathers in the gas collection chamber before being discharged, which acts as a buffer, making the exhaust pressure more uniform and the exhaust smoother.

[0008] In a further technical solution, a filter element and an exhaust plate are fixedly installed at the bottom of the lower body, the filter element covers the centralized exhaust port, and the exhaust plate covers the outside of the filter element.

[0009] By fixing a filter element and an exhaust plate to the bottom of the lower body, a dual protective structure is formed, which has the following beneficial effects: Filtration and protection: The filter element can be made of porous material, which can effectively block external dust and debris from entering the amplifier through the exhaust port, protecting the internal precision components; Noise reduction: The porous structure of the filter element has a certain noise reduction effect, which can reduce exhaust noise; Physical protection: The exhaust plate covers the outside of the filter element, which not only protects the filter element from external damage, but also ensures smooth exhaust through evenly distributed vent holes; Compact structure: The filter element and exhaust plate are integrated and installed at the bottom of the lower body, without increasing the overall size of the product.

[0010] A further technical solution is provided on the upper cover, which is connected to the A cavity. An adjustment rod is inserted into the flow adjustment port. The lower end of the adjustment rod extends into the flow adjustment port and is set as a conical structure. The bottom of the flow adjustment port is correspondingly set as a conical profile. An adjustable gap is formed between the conical structure at the lower end of the adjustment rod and the conical profile at the bottom of the flow adjustment port, which is used to adjust the gas flow between the A cavity and the C cavity.

[0011] By setting a tapered adjusting rod to cooperate with a tapered flow regulating port to form an adjustable gap, the following beneficial effects are achieved: The conical structure allows for stepless adjustment. By changing the screw depth of the adjustment rod, the gas flow between chamber A and chamber C can be precisely controlled, enabling fine-tuning of the amplifier's feedback characteristics. The tapered fit structure can achieve a large change in ventilation area within a small displacement range, resulting in high adjustment sensitivity; No complex adjustment mechanism is required; adjustment can be achieved through the contact of conical surfaces, resulting in low cost and high reliability.

[0012] In a further technical solution, the upper cover is also provided with a locking screw, the end of which can abut against the side wall of the adjusting rod to lock the position of the adjusting rod.

[0013] By setting a locking screw to lock the position of the adjusting rod, the following advantages are achieved: Position locking: After adjustment, tighten the locking screw to prevent the adjusting rod from loosening due to vibration or long-term use, and ensure the long-term stability of the adjustment parameters; Reliable anti-loosening: The end of the locking screw rests against the side wall of the adjusting rod and is locked by friction, making the structure simple and reliable; Easy to operate: Debugging and locking operations are simple, requiring no special tools, and are easy to maintain and adjust on site.

[0014] In a further technical solution, both the first and second membranes are completely encapsulated within the main body composed of the upper cover, middle plate, and lower body, and are not exposed to the external environment.

[0015] By completely encapsulating the first and second membranes inside the main body, the following beneficial effects are achieved: Environmental protection: The built-in diaphragm is protected by the main shell, which reduces the direct impact of drastic changes in ambient temperature on the diaphragm material. It effectively avoids the direct erosion and damage to the diaphragm by dust, rain, snow, ice and other elements in harsh outdoor environments, and significantly improves the product's environmental adaptability and service life. Aesthetics: The product has a simple and clean appearance with no exposed rubber parts, which improves the overall aesthetics and marketability of the product.

[0016] In a further technical solution, a valve core assembly is provided in the lower body, the valve core assembly including a valve core, a sealing nut and a locking nut; The lower body is provided with an air intake channel that communicates with the main air intake port. A circular hole is opened at the top of the air intake channel, and the air intake channel communicates with the C cavity through the circular hole. The valve core has a stepped shaft structure with a frustum in its middle. A part of the valve core is located in the air intake channel, and the other part extends upward through the circular hole into the C cavity. The frustum cooperates with the lower side of the circular hole to control the opening and closing of the circular hole.

[0017] By using a valve core with a frustum-shaped section to cooperate with a circular orifice to control the opening and closing of the main air passage, the following beneficial effects can be achieved: Reliable sealing: The frustum portion forms a contact seal with the lower side of the circular hole, providing good sealing performance and effectively preventing gas leakage; Sensitive action: The valve core slides up and down under the action of air pressure and spring force, with fast response speed and high control accuracy; Wear-resistant and durable: A rubber pad layer can be installed on the frustum section to reduce direct contact between metal parts and improve wear resistance and service life; Compact structure: The valve core integrates the air intake control function, eliminating the need for an additional valve seat and simplifying the structure.

[0018] A further technical solution also includes a piston assembly, which is composed of the second diaphragm, a clamp, a vent plate, and a gasket; The clamp is fixedly connected to the central area of ​​the second diaphragm, the vent plate is fixedly installed above the clamp, the vent plate has a plurality of connecting holes for connecting the B cavity and the C cavity, and the gasket is installed above the vent plate for sealing the upper part of the vent plate.

[0019] By assembling a piston assembly consisting of a second diaphragm, a clamp, a vent plate, and a gasket, the following advantages are achieved: Good airtightness: The second diaphragm is clamped and fixed together with the clamp and the vent plate to form a reliable seal and prevent gas leakage; Uniform exhaust: The evenly distributed circular connecting holes on the vent plate allow gas to flow into chamber B evenly, avoiding excessive local pressure. Convenient processing: The gasket is used to seal the machined holes and slots on the upper part of the vent plate, which facilitates the machining of the internal channels of the vent plate and reduces manufacturing costs; Smooth movement: The piston assembly moves as a whole, with uniform force distribution, resulting in smooth and reliable movement.

[0020] In a further technical solution, a pressure relief hole is provided in the middle of the clamp, the lower side of the pressure relief hole is set as an inclined surface, the sealing nut is set at the upper end of the valve core, and the top of the sealing nut can abut against the lower side of the pressure relief hole to control the opening and closing of the pressure relief hole.

[0021] By using a pressure relief hole in conjunction with a sealing nut to control the flow between chambers B and C, the following beneficial effects can be achieved: Rapid pressure relief: After the sealing nut is removed from the pressure relief hole, the high-pressure gas in chamber C can quickly flow into chamber B, achieving rapid pressure relief; Reliable sealing: The lower side of the pressure relief hole is set as an inclined slope, and the top of the sealing nut is set as a hemispherical structure to form a contact seal, resulting in good sealing performance; Wear-resistant design: Rubber pads can be embedded in the inclined surface to reduce direct contact between metal parts and improve service life; Synchronized action: The opening and closing of the pressure relief hole is matched with the movement position of the valve core, achieving precise air path switching control.

[0022] In a further technical solution, the exhaust plate is provided with multiple evenly distributed vent holes, and the exhaust plate is also provided with threaded holes for connecting a muffler.

[0023] By setting evenly distributed vent holes and threaded holes on the exhaust plate, the following beneficial effects are achieved: Smooth exhaust: Evenly distributed vents ensure smooth gas discharge and avoid excessive exhaust resistance; Scalability: The threaded hole can be connected to a standard industrial silencer as needed for field use, further reducing exhaust noise; Flexible adaptation: When the environment has strict requirements for noise, a silencer can be installed; when there are no special requirements, the filter and exhaust plate can be used directly to exhaust the air, which can meet the needs and reduce costs. Standardized design: The threaded holes adopt standard specifications, making it easy for users to select commercially available mufflers.

[0024] A further technical solution is that a filter screen is provided at the main air inlet of the lower body to filter the compressed air entering the amplifier.

[0025] By installing a filter screen at the main air intake, the following benefits are achieved: Intake air filtration: Performs preliminary filtration on the compressed air entering the amplifier to prevent impurities from entering precision components such as the valve core; Protect internal components: Prevent impurities from getting stuck in the valve core or wearing down the sealing surface, thereby improving product reliability and service life; Easy to maintain: The filter can be cleaned or replaced regularly, resulting in low maintenance costs.

[0026] In summary, the present invention, through the above technical solution, has the following overall beneficial effects compared with the prior art: Excellent waterproof and dustproof performance: With the fully built-in membrane structure and centralized exhaust port filter protection, it effectively prevents rainwater, dust and debris from the external environment from entering the amplifier. It is especially suitable for harsh environments such as outdoor pipelines, chemical plants, and coal mines. Optimized exhaust path design: The originally scattered exhaust channels are guided to the gas collection chamber through internal process holes and then discharged in a concentrated manner, realizing the reconstruction of the exhaust path. After the gas is collected, the pressure is more uniform and the exhaust is smoother, providing a structural basis for multiple protections. Low noise emissions: The porous structure of the filter element has a natural sound-absorbing effect, which can significantly reduce exhaust noise; for applications with higher noise requirements, the threaded holes on the exhaust plate can be connected to a muffler to further reduce noise to within the range allowed by industrial standards and improve the working environment. Wide temperature range adaptability: The built-in diaphragm is protected by the main body, avoiding the direct impact of drastic changes in ambient temperature on the rubber material, enabling the product to work stably in a wider temperature range and not fail due to freezing in the low-temperature environment of northern winters. Long life and high reliability: Multiple measures, such as built-in diaphragm protection, air intake filtration, exhaust protection, frustum sealing, and wear-resistant design of pressure relief holes, effectively extend the service life of key components; Precise and stable control performance: The combination of the tapered precision adjustment structure of the adjusting rod and the locking mechanism of the locking screw can not only achieve fine adjustment of the amplifier's operating characteristics, but also ensure the long-term stability of the debugging parameters, thus ensuring the accuracy and reliability of the pneumatic control system. Flexible adaptability: The pre-drilled threaded holes on the exhaust plate allow for the selection of whether or not to install a muffler, which not only meets the needs of different users and occasions, but also avoids unnecessary cost increases, reflecting the flexibility and economy of product design; Compact structure and easy maintenance: The overall structure is compact, and the components are rationally arranged. When maintenance is required, only the corresponding screws need to be removed to replace vulnerable parts such as filter elements and filter screens, without having to disassemble the entire amplifier, which greatly reduces maintenance difficulty and cost. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the internal cross-sectional structure of this application; Figure 2 This is a schematic diagram showing the locations of the exhaust passage, the gas collection chamber, and the exhaust collection passage in this application; Figure 3 This is a three-dimensional schematic diagram of this application; Figure 4 This is a schematic diagram of the installation and mating of the lower body and piston assembly in this application; Figure 5 This is a three-dimensional schematic diagram of the internal structure of the lower part of this application; Figure 6This is a three-dimensional schematic diagram of the plate in this application; Figure 7 This is a schematic diagram of the fit between the vent plate and the clamp in this application; Figure 8 This is a top view of this application; Figure 9 This application Figure 8 A cross-sectional view along the AA direction; In the diagram: 1. Plug; 2. Third O-ring seal; 3. Spring; 4. Filter screen; 5. Valve core; 6. Lower body; 7. Locking nut; 8. Sealing nut; 9. Clamp; 10. Second diaphragm; 11. Vent plate; 12. Middle plate; 13. First diaphragm; 14. Gasket; 15. Top cover; 16. Adjusting rod; 17. Locking screw; 18. First O-ring seal; 19. Second O-ring seal; 20. First screw; 21. Filter element; 22. Exhaust plate; 23. Second screw; 24. Socket headstock. 25. Column head screw spring washer assembly; 26. Fourth O-ring seal; 27. Flow regulating port; 28. Regulating channel; 29. ​​Lower channel; 30. Exhaust channel; 31. Gas collecting chamber; 32. Exhaust collecting channel; 33. Vent hole; 34. Connecting hole; 35. Guide hole; 36. Main air inlet hole; 37. Inlet channel; 38. Circular hole; 39. Pressure relief hole; 40. Positioner control air source inlet hole; 41. Main air outlet hole; 42. Frustum section; 43. Chamber A; 44. Chamber B; 45. Chamber C. Detailed Implementation

[0028] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0030] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0033] like Figures 1-9 As shown, the centralized exhaust pneumatic amplifier provided in this embodiment mainly includes three main parts: an upper cover 15, a middle plate 12, and a lower body 6, as well as a series of functional units installed inside and outside them.

[0034] The upper cover 15, middle plate 12, and lower body 6 are stacked sequentially from top to bottom, and are fixedly connected as a whole by a combination of hexagon socket head cap screws and spring washers 24. Specifically, the fixing holes on the upper cover 15 and middle plate 12 are through holes, while the fixing holes on the lower body 6 are threaded holes. During assembly, the hexagon socket head cap screws pass through the through holes of the upper cover 15 and middle plate 12 and are threaded into the threaded holes of the lower body 6, with spring washers providing anti-loosening protection. This connection method ensures the overall structural integrity while facilitating disassembly and maintenance.

[0035] Detailed structure and assembly relationship of each component: Top cover: The top cover 15 is the top component of this amplifier. It is made of metal materials (such as aluminum alloy) and has sufficient strength and good processing performance.

[0036] The upper cover 15 is provided with a flow regulating port 26, which communicates with cavity A 42. An regulating rod 16 is inserted into the flow regulating port 26. The regulating rod 16 is a slender rod-shaped structure, with its upper end extending outside the upper cover 15 for easy adjustment by the operator; its lower end extends into the flow regulating port 26 and is machined into a conical structure. The bottom of the flow regulating port 26 is correspondingly set with a conical profile, forming a conical hole that mates with the conical structure at the bottom of the regulating rod 16. This is used to adjust the gas flow between cavity A 42 and cavity C 44, achieving fine adjustment of the amplifier's operating characteristics. Specifically, when a larger gas flow is required, the regulating rod 16 is moved upwards, increasing the gap between the conical structure at the bottom of the regulating rod 16 and the conical profile at the bottom of the flow regulating port 26, thereby increasing the gas flow; conversely, the flow is decreased.

[0037] The upper cover 15 is also provided with a locking screw 17, which is installed in the threaded hole of the upper cover 15, and its end can abut against the side wall of the adjusting rod 16. After the adjusting rod 16 is adjusted to the appropriate position, tightening the locking screw 17 can lock the position of the adjusting rod 16, preventing it from being displaced due to vibration or other factors, and ensuring the stability of the adjustment parameters and the reliability of the pneumatic system.

[0038] The top of the cover 15 is provided with a positioner control air source inlet hole 39 that passes through the cover 15. The inner wall of the inlet hole is provided with internal threads for threaded connection with the air inlet pipe of the positioner control air source.

[0039] An annular sealing groove is provided at the contact surface between the upper cover 15 and the middle plate 12, and a sealing ring is installed in the annular sealing groove to achieve an airtight seal between the upper cover 15 and the middle plate 12. At the same time, the upper part of the adjusting rod 16 and the flow regulating port 26 are sealed by the first O-ring 18 to prevent gas from overflowing from the upper part of the flow regulating port 26.

[0040] Middle board part: The middle plate 12 is the intermediate component of this amplifier. It is also made of metal and has multiple air passages and mounting holes machined inside.

[0041] A first diaphragm 13 is press-fitted between the upper surface of the middle plate 12 and the upper cover 15. The first diaphragm 13 is a circular elastic diaphragm made of oil-resistant rubber or similar elastic material, which has good sealing performance and fatigue resistance. The edge of the first diaphragm 13 is clamped between the upper cover 15 and the middle plate 12. The bottom surface of the upper cover 15 is provided with an annular protrusion structure to press the first diaphragm 13, which serves both to fix it and to achieve a seal, preventing gas from escaping from the gap between the upper cover 15 and the middle plate 12. The central area of ​​the first diaphragm 13 cooperates with the lower piston assembly to transmit the driving force generated by the gas pressure.

[0042] A second diaphragm 10 is press-fitted between the lower surface of the middle plate 12 and the lower body 6. The structure and material of the second diaphragm 10 are similar to those of the first diaphragm 13. Its edge is clamped between the middle plate 12 and the lower body 6, and its central region is fixedly connected to the clamp 9, forming the movable part of the piston assembly.

[0043] The middle plate 12 has multiple air passages machined inside, including an adjustment channel 27 connecting chamber A 42 and chamber C 44, and an exhaust channel 29 connecting chamber B 43 and the gas collecting chamber 30. Among them, the adjustment channel 27 is connected to the flow adjustment port 26, and a second O-ring 19 is provided at the joint between the adjustment channel 27 and the flow adjustment port 26 to form a seal and prevent gas from escaping from the joint gap.

[0044] Lower body part: The lower body 6 is the bottom component of this amplifier, and it has multiple chambers, air passages and mounting holes machined inside.

[0045] A cavity B 43 and a cavity C 44 are formed between the upper part of the lower body 6 and the middle plate 12. The cavity C 44 is located below the second diaphragm 10, and the cavity B 43 is located between the first diaphragm 13 and the second diaphragm 10.

[0046] The lower body 6 has a main air inlet 35 with internal threads on its inner wall for easy connection to the main air pipe. An air intake channel 36 is located in the middle of the lower body 6, communicating with the main air inlet 35. A circular hole 37 is located at the top of the air intake channel 36, connecting it to the C-cavity 44. A lower channel 28 is also provided on the lower body 6, connecting the adjustment channel 27 and the C-cavity 44. A main air outlet 40 is also provided on the lower body 6, communicating with the C-cavity 44. The main air outlet 40 has internal threads on its inner wall for connection to the pipes of an external actuator.

[0047] A valve core assembly is installed in the center of the lower body 6. This valve core assembly includes a sealing nut 8, a locking nut 7, and a valve core 5. Specifically, the valve core 5 has a stepped shaft structure. One part of the valve core 5 is located in the air intake channel 36, and the other part extends upward through the circular hole 37 into the C-cavity 44. A frustum 41 is provided in the middle of the valve core 5. The bottom part of the valve core 5 is slidably disposed in the guide hole 34. The guide hole 34 is opened on the plug 1, and the plug 1 is fixed to the bottom of the lower body 6 and fastened by the first screw 20, which can be an internal hexagonal head screw. The sealing nut 8 is threaded to the upper end of the valve core 5 and locked by the locking nut 7 to ensure a reliable connection. The lower end of the valve core 5 abuts against the upper end of the spring 3, and the spring 3 is installed in the guide hole 34. Its lower end is limited by the plug 1.

[0048] The plug 1 is a circular cap-shaped structure, which is fixedly installed in the air collection chamber 30 at the bottom of the lower body 6 by the first screw 20. It can seal the bottom opening of the air intake channel 36. At the contact point between the plug 1 and the lower body, a third O-ring seal 2 is provided to prevent gas from directly entering the air collection chamber 30 from the bottom of the air intake channel 36. The spring 3 has a certain pre-compression during assembly and always applies an upward thrust to the valve core 5.

[0049] The lower body 6 has several exhaust collection channels 31 inside. In this embodiment, there are four exhaust collection channels 31 evenly distributed, and correspondingly, there are also four exhaust channels 29 evenly distributed. The number can be adjusted as needed. The top of the exhaust collection channel 31 communicates with the exhaust channel 29 in the middle plate 12, and a fourth O-ring seal 25 is provided at the connection. The bottom of the exhaust collection channel 31 communicates with the gas collection chamber 30. The exhaust collection channel 31 collects the discharged gas into the gas collection chamber 30 for collecting the gas discharged when the amplifier is working.

[0050] A filter element 21 and an exhaust plate 22 are fixedly installed at the bottom of the lower body 6, covering the bottom opening of the gas collection chamber 30. The filter element 21 is a cylindrical structure made of porous materials (such as sintered bronze, stainless steel mesh, etc.), which has good filtration performance and a certain degree of noise reduction. The exhaust plate 22 is a circular plate structure installed at the bottom of the gas collection chamber 30, with multiple evenly distributed vent holes 32 for smooth gas discharge. The filter element 21 can be located outside the bottom opening of the gas collection chamber 30, and the exhaust plate 22 covers the outside of the filter element 21. The two can be fixedly installed at the bottom of the lower body 6 by a second screw 23, forming a complete exhaust protection structure. The second screw can be an internal hexagonal head screw.

[0051] As a preferred embodiment, the exhaust plate 22 may also be machined with threaded holes that communicate with the exhaust port for connecting a standard industrial silencer as needed for on-site use. When the environment has strict noise requirements, users can choose to install a silencer to further reduce exhaust noise; when there are no special requirements, the filter element 21 and exhaust plate 22 can be used directly for exhaust, simplifying the structure and reducing costs. This design reflects the product's flexibility and adaptability.

[0052] A filter screen 4 (not shown in detail in the figure) is also provided at the connection between the main air inlet 35 and the air inlet channel 36 of the lower body 6. The filter screen 4 is used to filter the compressed air entering the amplifier to prevent impurities from entering precision components such as the valve core 5, thereby improving the reliability and service life of the product.

[0053] To ensure the airtightness of each gas passage, O-rings are installed at the contact surface between the lower body 6 and the middle plate 12, as well as at each process hole. These O-rings form a reliable seal at the connection of each component to prevent gas leakage.

[0054] Piston assembly: The piston assembly consists of a second diaphragm 10, a clamp 9, a vent plate 11, and a gasket 14.

[0055] As described above, the second diaphragm 10 has its edges clamped and fixed, while its central region can move up and down. The clamp 9 is a disc-shaped structure, fixedly connected to the central region of the second diaphragm 10, used to transmit the movement of the diaphragm. The vent plate 11 is located below the first diaphragm 13 and is fixedly installed above the clamp 9, together with the clamp 9 clamping the second diaphragm 10. The second diaphragm 10 is annular, with a through hole in its center, facilitating through-mounting of the clamp and clamping the inner edge of the second diaphragm together with the vent plate 11. The outer edge of the second diaphragm is clamped by the middle plate 12 and the lower body 6. The vent plate 11 has multiple connecting holes 33 for connecting cavity B 43 and cavity C 44. The connecting holes 33 are evenly distributed in a circular shape on the outer periphery of the vent plate 11.

[0056] The gasket 14 is installed above the vent plate 11 to seal the upper part of the vent plate 11. Because when processing the connecting hole 33, it is necessary to cut a groove inside the vent plate 11 for easy processing, so a hollow groove is processed on the upper part of the vent plate 11. When assembling and using, the top of the groove needs to be sealed so that air can be evenly discharged from the connecting hole 33. Therefore, the gasket 14 is set.

[0057] The entire piston assembly can move up and down relative to the middle plate 12 and the lower body 6 under the drive of the second diaphragm 10, thereby realizing the function of switching the air path.

[0058] Valve core and sealing structure: The plug 1 has a guide hole 34, and the bottom part of the valve core 5 is slidably disposed in the guide hole 34 to ensure that the movement of the valve core 5 is smooth and reliable.

[0059] The valve core 5 has a frustum 41, the minimum diameter of which is smaller than the diameter of the circular hole 37, and the maximum diameter of which is larger than the diameter of the circular hole 37. The frustum 41 controls the opening and closing of the circular hole 37: when the valve core 5 moves upward, the frustum 41 abuts against the lower side of the circular hole 37, and the circular hole 37 is closed by the valve core 5. At this time, the main air inlet 35 is not connected to the C chamber 44; when the valve core 5 moves downward, the frustum 41 disengages from the lower side of the circular hole 37, and the circular hole 37 is no longer closed by the valve core 5. At this time, the main air inlet 35 is connected to the C chamber 44. To enhance the sealing performance, a rubber gasket layer can be provided on the frustum 41.

[0060] A pressure relief hole 38 is provided in the middle of the clamp 9, and the lower side of the pressure relief hole 38 is set as an inclined surface. The top of the sealing nut 8 can be a hemispherical structure or a frustum structure; in this embodiment, a hemispherical structure is used. To improve the sealing performance, a rubber pad is provided on the inclined surface of the lower side of the pressure relief hole 38, which can be embedded. The sealing nut 8 can abut against the lower side of the pressure relief hole 38 to control the opening and closing of the pressure relief hole 38: when the sealing nut 8 moves upward and tightens, the pressure relief hole 38 is closed; when the sealing nut 8 moves downward and disengages, the pressure relief hole 38 is opened, and cavity C 44 and cavity B 43 are connected.

[0061] Chamber definition: To facilitate understanding of the subsequent working principle, the chambers are first defined as follows: A cavity 42: Located between the upper cover 15 and the first diaphragm 13, it is connected to the air inlet 39 of the positioner control air source and receives input air pressure signals.

[0062] B cavity 43: Located between the first diaphragm 13 and the second diaphragm 10, i.e. the internal space of the middle plate 12, it is always connected to the gas collection chamber 30 through the exhaust channel 29 on the middle plate 12 and is maintained at atmospheric pressure.

[0063] C-cavity 44: Located between the second diaphragm 10 and the lower body 6, it is connected to the main air outlet 40 (leading to the external actuator), and its pressure varies with the working state of the actuator.

[0064] Fully integrated diaphragm structure: Both the first diaphragm 13 and the second diaphragm 10 are completely encapsulated within the main body composed of the upper cover 15, the middle plate 12, and the lower body 6, with no part exposed to the external environment. This structural design has the following advantages: Environmental protection: It effectively avoids the direct erosion and damage to the membrane by dust, rain, snow, ice and other factors in harsh outdoor environments, and significantly improves the product's environmental adaptability and service life.

[0065] Temperature adaptability: The built-in diaphragm is protected by the main body shell, which reduces the direct impact of drastic changes in ambient temperature on the diaphragm material, allowing the product to work normally in a temperature range of -40℃ to +80℃.

[0066] Aesthetics: The product has a simple and clean appearance with no exposed rubber parts, which improves the overall aesthetics and marketability of the product.

[0067] Centralized exhaust and protective structure: Traditional amplifiers have their exhaust vents directly exposed, making them the most vulnerable part of the product to environmental influences. This invention completely solves this problem through the following design: Exhaust path reconstruction: The original multiple dispersed exhaust channels are guided to the gas collection chamber 30 inside the lower body 6 through internal process holes (machined inside the lower body 6 and the middle plate 12) to achieve gas collection.

[0068] Centralized exhaust: The gas in the gas collection chamber 30 is discharged through a centralized exhaust port at the bottom of the lower body 6, which facilitates the installation of protective devices.

[0069] Dual protection: A filter element 21 is installed at the exhaust port. This filter element can effectively block external dust and debris from entering the amplifier through the exhaust port. On the other hand, its porous structure has a certain sound-dampening effect, which can reduce exhaust noise. An exhaust plate 22 is also provided on the outside of the filter element 21, which not only protects the filter element from external damage, but also ensures smooth exhaust through evenly distributed vent holes 32.

[0070] Expandability: The pre-drilled threaded holes on the exhaust plate 22 can be used to connect a muffler as needed to further reduce exhaust noise and meet the needs of different users.

[0071] Precision adjustment and locking mechanism: The mating design of the adjusting rod 16 and the locking screw 17 enables precise adjustment and reliable locking of the amplifier's operating characteristics. Conical adjustment: The conical structure at the lower end of the adjusting rod 16 matches the conical profile at the bottom of the flow regulating port 26. By changing the screw-in depth of the adjusting rod 16, the gas flow between cavity A 42 and cavity C 44 can be precisely controlled, thereby achieving fine-tuning of the amplifier feedback characteristics.

[0072] Locking and anti-loosening: After adjustment, tighten the locking screw 17 so that its end presses against the side wall of the adjusting rod 16. Use friction to prevent the adjusting rod 16 from loosening due to vibration or long-term use, and ensure the long-term stability of the adjustment parameters.

[0073] Working principle: The working principle of this invention will be explained in detail below, taking into account the gas flow path and the motion state of each component.

[0074] Those skilled in the art typically refer to the main air intake end as P2, the main air outlet end as Port A, and the end used to connect to the positioner control air path as P1.

[0075] State 1: Initial state (no ventilation) When compressed air has not yet been introduced into the amplifier, all chambers are at atmospheric pressure.

[0076] At this time, the valve core 5 is in its highest position under the upward thrust of the spring 3. The frustum 41 of the valve core 5 abuts against the lower side of the circular hole 37, forming a contact seal, which closes the circular hole 37 between the main air inlet 35 and the main air outlet 40, so that the main air inlet 35 (P2) and the main air outlet 40 (A port) are not connected, and the main air circuit is in a closed state.

[0077] At the same time, the sealing nut 8 rises to its highest point along with the valve core 5, and comes into close contact with the clamp 9 in the piston assembly (specifically, with the lower side of the pressure relief hole 38), forming a reliable contact seal. Due to the upward thrust of the sealing nut 8, the entire piston assembly (including the clamp 9, the vent plate 11, and the second diaphragm 10) is lifted up, and the second diaphragm 10 is in an upward convex state.

[0078] In this state, all gas circuits are either closed or in standby mode, awaiting the arrival of an input signal.

[0079] State 2: Intake working state When the positioner controls the air inlet 39 (P1) to start supplying compressed air, high-pressure gas enters chamber A 42, causing the pressure in chamber A 42 to rise rapidly. Since chamber B 43 is always connected to the atmosphere through the exhaust channel and is maintained at atmospheric pressure, the pressure in chamber A 42 is greater than the pressure in chamber B 43, creating a pressure difference across the first diaphragm 13.

[0080] Under this pressure difference, the central region of the first diaphragm 13 bulges downward, pushing the piston assembly downward against the thrust of the spring 3. The downward movement of the piston assembly is transmitted to the sealing nut 8 and the valve core 5 through the clamp 9, causing the valve core 5 to also move downward.

[0081] After the valve core 5 moves downward, its frustum 41 disengages from the lower side of the circular hole 37, and the main air inlet 35 and the main air outlet 40 are connected. High-pressure gas flows from the main air inlet 35 through the inlet channel 36 and the circular hole 37 into the C chamber 44, then into the main air outlet 40, and finally into the external actuator, driving the actuator to start operating.

[0082] Meanwhile, the high-pressure gas in chamber A 42 flows slowly into chamber C 44 through the tiny gap between the tapered structure at the lower end of the regulating rod 16 and the bottom of the flow regulating port 26, via the regulating channel 27 and the lower channel 28, causing the pressure in chamber C 44 to gradually increase. The increase in pressure in chamber C 44 acts on the lower part of the second diaphragm 10, balancing the force exerted by the pressure in chamber A 42 on the upper part of the first diaphragm 13, and together they resist the thrust of the spring 3.

[0083] In this state, the displacement of valve core 5 depends on the balance between the air pressure in chamber A 42 and the thrust of spring 3. When the air pressure in chamber A 42 increases, the downward movement of valve core 5 increases, the opening between the main air inlet 35 and the main air outlet 40 increases, and the amount of air entering the actuator increases; conversely, when the air pressure in chamber A 42 decreases, valve core 5 moves upward under the action of spring 3, and the opening decreases. In this way, precise pneumatic control of the actuator is achieved.

[0084] State 3: Pressure Relief and Reset State When the actuator needs to be depressurized (i.e., stop working or reverse movement), the control system cuts off the air supply to the positioner control air source inlet 39, and the air pressure in chamber A 42 gradually decreases until it approaches atmospheric pressure.

[0085] At this time, the pressure in chamber C 44 (i.e., the pressure inside the actuator) is still relatively high, greater than the atmospheric pressure in chamber B 43. Under the action of the pressure difference, the second diaphragm 10 is subjected to an upward thrust. At the same time, due to the decrease in pressure in chamber A 42, the thrust acting on the first diaphragm 13 decreases, and the upward thrust of the spring 3 relatively increases.

[0086] Under the pressure difference between chamber B 43 and chamber C 44, the second diaphragm 10 pushes the piston upward, and under the thrust of the spring 3, the valve core 5 begins to move upward to reset. The upward movement of the valve core 5 first causes the frustum portion 41 to reseal the circular hole 37 between the main air inlet 35 and the main air outlet 40, cutting off the main air supply and stopping the supply of air to the actuator.

[0087] After the valve core 5 closes the circular hole 37, it stops moving. However, at this time, the second diaphragm 10 continues to be in an upward state under the gas pressure in chamber C 44, causing the sealing surface between the sealing nut 8 and the clamp 9 to disengage, forming a gap. This gap allows the pressure relief hole 38 to no longer be closed, and chamber B 43 and chamber C 44 to connect.

[0088] The high-pressure gas in chamber C 44 then flows into chamber B 43 through the pressure relief hole 38, and then enters the gas collection chamber 30 of the lower body 6 through the exhaust channel 29 on the middle plate 12 and the exhaust collection channel 31 on the lower body 6. Finally, it is discharged into the atmosphere through the filter element 21 and the exhaust plate 22, thus realizing the pressure relief of the actuator.

[0089] During the depressurization process, the pressure in chamber C 44 gradually decreases, while the pressure in chamber B 43 temporarily increases (but is quickly released through the exhaust channel), and the upward thrust on the second diaphragm 10 gradually decreases. When the pressure in chamber C 44 decreases to be equal to the pressure in chamber B 43 (i.e., atmospheric pressure), the pressure on the second diaphragm 10 is balanced, the second diaphragm 10 returns to its original position, the sealing nut 8 re-engages tightly with the clamp 9, and the communication channel between chamber B 43 and chamber C 44 is cut off.

[0090] At this point, cavity A42, cavity B43, and cavity C44 have all returned to their initial atmospheric pressure state, and the entire amplifier returns to state one, waiting for the next working cycle.

[0091] Debugging method: After the amplifier is assembled, it needs to be debugged to ensure that its performance meets the design requirements. The specific debugging steps are as follows: Step 1: Initial Installation Install the amplifier correctly onto the valve positioner system according to the drawings, connect all air lines, and check that all connections are secure and that the seals are good.

[0092] Step 2: Coarse adjustment lever Loosen the locking screw 17 and use a suitable tool to rotate the adjusting rod 16 to the appropriate depth. Based on experience, the adjusting rod 16 is usually first screwed in until it just touches the bottom of the tapered hole, and then backed out about 1 / 4 to 1 / 2 turn to maintain a small gas communication channel between chamber A 42 and chamber C 44.

[0093] Step 3: Ventilation Test Introduce compressed air at rated pressure into the main air inlet 35 (P2) and observe the operation of the actuator. Use external testing equipment to test parameters such as the actuator's response speed and positioning accuracy.

[0094] Step 4: Fine-tune the adjustment lever Based on the test results, the screw-in depth of the fine-tuning lever 16 is as follows: If the actuator responds too slowly (with a large lag), the adjusting rod 16 can be rotated out appropriately (to reduce the screw-in depth) to increase the connection between cavity A 42 and cavity C 44 and improve the feedback speed. If the actuator oscillates or becomes unstable, the adjusting rod 16 can be screwed in appropriately (increasing the screwing depth) to reduce the flow and increase the system damping.

[0095] After each minor adjustment, the ventilation test is repeated until all performance indicators meet the design requirements.

[0096] Step 5: Lock the adjusting lever After adjustment, keep the adjusting rod 16 stationary and tighten the locking screw 17 so that the end of the locking screw 17 firmly presses against the side wall of the adjusting rod 16 to prevent it from loosening. The tightening torque should be appropriate to ensure reliable locking while avoiding damage to the threads or components.

[0097] Step 6: Final Inspection Perform another ventilation test to confirm that the performance parameters remain unchanged after locking. Check all connections for leaks, ensure smooth exhaust flow, and verify that filter element 21 and exhaust plate 22 are securely installed.

[0098] Step 7: Installation of optional accessories If the operating environment has strict requirements for noise, a suitable muffler can be installed on the threaded hole of the exhaust plate 22. When installing, ensure that the muffler specifications match the exhaust volume and that the connection is secure and well-sealed.

[0099] Beneficial effects Through the above structural design and working principle, the present invention has the following advantages over the prior art: Excellent waterproof and dustproof performance: With built-in membrane and exhaust port filter protection, it effectively prevents rainwater, dust and debris from the external environment from entering the amplifier. The product protection level can reach IP65 or above, making it particularly suitable for harsh environments such as outdoor pipelines, chemical plants, and coal mines.

[0100] Wide temperature range adaptability: The built-in diaphragm is protected by the main body, avoiding the direct impact of drastic changes in ambient temperature on the rubber material, enabling the product to work stably in a wide temperature range of -40℃ to +80℃, and will not fail due to freezing in the low-temperature environment of northern winters.

[0101] Low noise emissions: The porous structure of filter element 21 has a natural sound-absorbing effect, which can significantly reduce exhaust noise. For applications with higher noise requirements, a muffler can be installed to further reduce noise to within the limits allowed by industrial standards, thus improving the working environment.

[0102] Long lifespan and high reliability: Multiple protective measures, including built-in diaphragm protection, intake filtration, and exhaust protection, effectively extend the service life of critical components. Accelerated life testing has verified that the mean time between failures (MTBF) of this invention is more than 50% higher than that of traditional products.

[0103] Precise and stable control performance: The combination of the tapered precision adjustment structure of the adjusting rod 16 and the locking mechanism of the locking screw 17 can not only achieve fine adjustment of the amplifier's operating characteristics, but also ensure the long-term stability of the debugging parameters, thus ensuring the accuracy and reliability of the pneumatic control system.

[0104] Flexible adaptability: The threaded holes on the exhaust plate 22 allow for the selection of whether or not to install a muffler, which not only meets the needs of different users and different occasions, but also avoids unnecessary cost increases, reflecting the flexibility and economy of product design.

[0105] Compact structure and easy maintenance: The overall structure is compact and the components are rationally arranged. When maintenance is required, only the corresponding screws need to be removed to replace vulnerable parts such as filter element 21 and filter screen 4, without having to disassemble the entire amplifier, which greatly reduces the difficulty and cost of maintenance.

[0106] Other implementation methods: The materials of each component can be selected according to the specific usage environment. For example, fluororubber diaphragms can be used in high-temperature environments, while stainless steel bodies can be used in corrosive environments. The shape and structure of filter element 21 can be adjusted according to the installation space and filtration requirements, such as using a square or oval shape; The number, size, and distribution of vents on the exhaust plate 22 can be optimized according to exhaust volume and noise requirements; For any parts not mentioned in this application, existing technologies may be used or referenced.

[0107] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0108] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A centralized exhaust pneumatic amplifier, comprising an upper cover (15), a middle plate (12), and a lower body (6) stacked and fixedly connected from top to bottom, wherein a first diaphragm (13) is press-fitted between the upper cover (15) and the middle plate (12), and a second diaphragm (10) is press-fitted between the middle plate (12) and the lower body (6), wherein a cavity A (42) is formed between the first diaphragm (13) and the upper cover (15), a cavity B (43) is formed between the first diaphragm (13) and the second diaphragm (10), and a cavity C (44) is formed between the second diaphragm (10) and the lower body (6), characterized in that: The lower body (6) is provided with an air collection chamber (30); The middle plate (12) is provided with at least one exhaust channel (29) that communicates with the B cavity (43). The lower body (6) is provided with at least one exhaust collection channel (31) that corresponds to and communicates with the exhaust channel (29) one by one, and the bottom of the exhaust collection channel (31) is connected to the gas collection chamber (30). The bottom of the gas collection chamber (30) is provided with a centralized exhaust port. The gas in the B chamber (43) is collected in the gas collection chamber (30) through the exhaust channel (29) and the exhaust collection channel (31) in sequence, and then discharged through the centralized exhaust port.

2. The centralized exhaust pneumatic amplifier according to claim 1, characterized in that, The bottom of the lower body (6) is fixedly installed with a filter element (21) and an exhaust plate (22). The filter element (21) covers the central exhaust port, and the exhaust plate (22) covers the outside of the filter element (21).

3. A centralized exhaust pneumatic amplifier according to claim 1, characterized in that, The upper cover (15) is provided with a flow regulating port (26) communicating with the A cavity (42). An regulating rod (16) is inserted into the flow regulating port (26). The lower end of the regulating rod (16) extends into the flow regulating port (26) and is set as a conical structure. The bottom of the flow regulating port (26) is correspondingly set as a conical profile. An adjustable gap is formed between the conical structure at the lower end of the regulating rod (16) and the conical profile at the bottom of the flow regulating port (26) for adjusting the gas flow between the A cavity (42) and the C cavity (44).

4. A centralized exhaust pneumatic amplifier according to claim 3, characterized in that, The upper cover (15) is also provided with a locking screw (17), the end of which can abut against the side wall of the adjusting rod (16) to lock the position of the adjusting rod (16).

5. A centralized exhaust pneumatic amplifier according to claim 1, characterized in that, The first diaphragm (13) and the second diaphragm (10) are completely encapsulated inside the main body composed of the upper cover (15), the middle plate (12) and the lower body (6), and are not exposed to the external environment.

6. A centralized exhaust pneumatic amplifier according to claim 1, characterized in that, The lower body (6) is provided with a valve core assembly, which includes a valve core (5), a sealing nut (8) and a locking nut (7). The lower body (6) is provided with an air intake channel (36) that communicates with the main air intake hole (35). A circular hole (37) is opened at the top of the air intake channel (36). The air intake channel (36) communicates with the C cavity (44) through the circular hole (37). The valve core (5) has a stepped shaft structure with a frustum (41) in the middle. A part of the valve core (5) is located in the air intake channel (36), and the other part extends upward through the circular hole (37) into the C cavity (44). The frustum (41) cooperates with the lower side of the circular hole (37) to control the opening and closing of the circular hole (37).

7. A centralized exhaust pneumatic amplifier according to claim 6, characterized in that, It also includes a piston assembly, which consists of the second diaphragm (10), a clamp (9), a vent plate (11), and a gasket (14); The clamp (9) is fixedly connected to the central area of ​​the second diaphragm (10), the vent plate (11) is fixedly installed above the clamp (9), the vent plate (11) has a plurality of connecting holes (33) for connecting the B cavity (43) and the C cavity (44), and the gasket (14) is installed above the vent plate (11) for sealing the upper part of the vent plate (11).

8. A centralized exhaust pneumatic amplifier according to claim 7, characterized in that, The clamp (9) has a pressure relief hole (38) in the middle. The lower side of the pressure relief hole (38) is set as an inclined surface. The sealing nut (8) is set at the upper end of the valve core (5). The top of the sealing nut (8) can abut against the lower side of the pressure relief hole (38) to control the opening and closing of the pressure relief hole (38).

9. A centralized exhaust pneumatic amplifier according to claim 2, characterized in that, The exhaust plate (22) has multiple evenly distributed vent holes (32) and threaded holes for connecting a muffler.

10. A centralized exhaust pneumatic amplifier according to claim 1, characterized in that, A filter (4) is provided at the main air inlet (35) of the lower body (6) to filter the compressed air entering the amplifier.

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